Significant increases in BALF MMP-1 protein levels (0.8±4.5 ng/ml in control, 3.0±3.0 ng/ml in smokers, 2.7±3.0 ng/ml in emphysema; p<0.0001 by Kruskal-Wallis test, all data are presented as mean ± standard error) (Figure 1A) and MMP-9 protein levels (2.1±9.2 ng/ml in control, 7.5±15.4 ng/ml in smokers, 24.9±44.7 in emphysema; p<0.0001 by Kruskal-Wallis test) (Figure 1B) were detected amongst the three cohorts. The gene discussed is MMP9; the disease is pulmonary emphysema.